2023 Volume 68 Issue 6 Pages 381-386
The electrification of automobiles is progressing rapidly with the tightening of exhaust gas regulations and the demand for low fuel consumption worldwide. EVs do not have an internal combustion engine as a power source or power generator, it has a short cruising range, which is a major obstacle for users. Therefore, it is essential to expand the cruising range for the further spread of EVs in the future. Consideration is being given to combining EVs with transmissions to extend cruising range. Most of the EVs currently on the market do not have a transmission and use a reduction mechanism with a fixed reduction ratio. This is because the motor can generate a large torque from the start and can cover high revolution, so a transmission with a wide range of gear ratios,which has been used in internal combustion engines, is not essential. However, it is expected that transmissions will also be used in high-end electrified sports cars and SUVs because it will be possible not only to extend cruising range but also to increase maximum torque and maximum vehicle speed. This paper introduces the relatively latest transmission technology for EVs that has been researched so far.
